The present invention relates to a structure and a production method of apparatus such as a propeller shaft usable for a motor vehicle.
A propeller shaft as disclosed in JP 2013-194895 A (corresponding to US 2013/0252748A1 Sugiyama et al.) is a shaft or shaft assembly for transmitting rotation from a drive source of a vehicle to a drive wheel or drive wheels. A shaft section of the propeller shaft extends in a longitudinal direction of the vehicle from a first shaft end to a second shaft end, and a constant velocity joint is provided between the first shaft end and a first shaft of a ferrous metallic material provided between the shaft section and the drive source, or between the second shaft end and a second shaft of a ferrous metallic material provided between the shaft section and the drive wheel(s).
The constant velocity joint includes: an outer cylindrical member or outer race provided at the first or second shaft end of the shaft section; an inner cylindrical member or inner race of a ferrous metallic material, disposed in the outer cylindrical member and coupled with the first or second shaft inserted in the inner cylindrical member, to enable transmission of a rotational torque between the inner cylindrical member and the first or second shaft; a plurality of balls disposed between the inner and outer cylindrical members for the torque transmission therebetween; and a sleeve member formed of a ferrous metallic material in the form of a hollow cylinder or tube, connected with an end portion of the inner cylindrical member on a side opposite to the shaft section and arranged to receive the first or second shaft inserted in the sleeve member.
The constant velocity joint further includes a seal member or seal ring to seal an annular clearance between the outside circumferential surface of the first or second shaft and the inside circumferential surface of the sleeve member liquidtightly. With this seal member, the constant velocity joint prevents entry of rain water through the clearance between the first or second shaft and the sleeve member, and eventually prevent sticking between the outside circumferential surface of the first or second shaft and the inside circumferential surface of the sleeve member due to rust formed by the rain water.